Microsoft is marking New York City's Fashion Week with the introduction of designer palettes and wallpapers for Windows-powered mobile phones and devices.

The downloadable add-ons include works by several top design and fashion icons, including Vera Wang, Diane von Furstenberg, Isaac Mizrahi, Rock & Republic, and Ron Arad. The downloads will be available on Oct. 6, when Microsoft is expected to introduce a range of new cell phones equipped with Windows Mobile 6.5.

"We feel the designer themes are great examples of how Windows phones are moving into the consumer space and our Windows phone offerings on October 6 will continue this expansion of the brand," said Microsoft marketing manager Liz Sloan, in a blog post Monday.

"Smartphones are just as much a fashion statement as the clothes you wear and are quickly becoming a must-have accessory," added Sloan. "The designer themes are just one more way that Windows phones help folks customize their devices to fit their style," she said.

The add-ons will be available for free download to all phones running Windows Mobile 6.5 through Microsoft's Windows Marketplace for Mobile.

The Fashion Week campaign is Microsoft's latest effort to promote Windows Mobile, but the company also is hedging its bets by developing software for other platforms. Nokia's open source Symbian owns about half the worldwide mobile OS market, while Windows Mobile controls less than 10%, according to the most recent numbers from research group Gartner.

Microsoft and Nokia announced a broad alliance last month under which the two companies will work together to optimize Microsoft applications, including the Office productivity suite, for use on Nokia's mobile devices.

The agreement calls for the mobile version of Microsoft Office to run on Symbian.

The first line of Nokia phones to be covered under the pact is the business-oriented Eseries. Microsoft and Nokia will also co-develop mobile middleware and other tools, including Exchange ActiveSync, to help businesses integrate Nokia mobile devices into their Microsoft enterprise computer networks. Nokia also plans to ship Microsoft Office Communicator Mobile on its phones starting in 2010.

NYC Fashion Week runs from Sept. 10-17.

InformationWeek has published an in-depth report on smartphone security. Download the report here (registration required).